In working through my experiment, I encountrered many obstacles. I'm still uncertain as to why it was not successful and the only thing I can speculate on is that I didn't use proper proportions of the solutions. I decided it would be most economically efficient if I simply reduced my measurements so that if the first few didn't work, then I wouldn't have wasted a full solution worth of materials.
I tried two different vessels in my practice runs - a beer bottle, and a shot glass. I thought the beer bottle would work well because it would be easy to stopper if the reaction worked and was also easy to swirl. However neither succeeded. As the year wound down to a close, and exams were imminent, I decided it was best to merely speculate on why it didn't work properly rather than dedicate anymore time to trying to make it work. I would however like to try it again at some point this summer as it would be a really cool experiment to have as a keepsake!
In presenting this to the grade 9 class, I would have tried to make it as appealing as possible, while still portraying important facts to them. A grade 9 applied science class would be more geared to seeing a "WOW" factor, as opposed to the actual chemistry and logistics, and the "WHY" factor.
I would have given them a brief introduction on what the silver mirror experiment is all about, and how dextrose is a reducing sugar. I would have probably explained the difference between an aldehyde and a ketone, even though that knowledge is way beyond them at this point in their chemistry know-how. Then would come the "WOW" factor. I would have prepared all the solutions fresh shortly before the class started so they would be at optimal functioning capacity, and so the class didn't lose interest while I prepared the solutions in front of them. I would then line up my reaction vessels and introduce the chemical solutions I would be adding - not that they would particularily care, but just for science sake. Then I would swirl the contents. The reaction takes between two and five minutes to fully occur, but I would entertain them with a musical interlude of some sort in between the two stages.
Once the reaction was complete, I would stopper the vessel and do a small quiz to see who was paying attention. I would ask simple questions like what was the name of the sugar I put into the reaction (dextrose), what the reagent was called (Tollens'), etc. and the students who were able to answer my questions would receive one of the silvered containers as a prize.
I tried two different vessels in my practice runs - a beer bottle, and a shot glass. I thought the beer bottle would work well because it would be easy to stopper if the reaction worked and was also easy to swirl. However neither succeeded. As the year wound down to a close, and exams were imminent, I decided it was best to merely speculate on why it didn't work properly rather than dedicate anymore time to trying to make it work. I would however like to try it again at some point this summer as it would be a really cool experiment to have as a keepsake!
In presenting this to the grade 9 class, I would have tried to make it as appealing as possible, while still portraying important facts to them. A grade 9 applied science class would be more geared to seeing a "WOW" factor, as opposed to the actual chemistry and logistics, and the "WHY" factor.
I would have given them a brief introduction on what the silver mirror experiment is all about, and how dextrose is a reducing sugar. I would have probably explained the difference between an aldehyde and a ketone, even though that knowledge is way beyond them at this point in their chemistry know-how. Then would come the "WOW" factor. I would have prepared all the solutions fresh shortly before the class started so they would be at optimal functioning capacity, and so the class didn't lose interest while I prepared the solutions in front of them. I would then line up my reaction vessels and introduce the chemical solutions I would be adding - not that they would particularily care, but just for science sake. Then I would swirl the contents. The reaction takes between two and five minutes to fully occur, but I would entertain them with a musical interlude of some sort in between the two stages.
Once the reaction was complete, I would stopper the vessel and do a small quiz to see who was paying attention. I would ask simple questions like what was the name of the sugar I put into the reaction (dextrose), what the reagent was called (Tollens'), etc. and the students who were able to answer my questions would receive one of the silvered containers as a prize.